【VC++】万年历算法代码。根据年月日求星期。。

BOOL IsLeapYear(unsigned int nYear)
{
	if((nYear % 4 ==0 && nYear % 400 != 0) ||(nYear % 400 == 0))
	{
		return TRUE;
	}
	else
	{
		return FALSE;
	}
}
unsigned int MonthOfDays(unsigned int nYear,unsigned int nMonth)
{
	switch(nMonth)
	{
	case 1:
	case 3:
	case 5:
	case 7:
	case 8:
	case 10:
	case 12:
		{
			return 31;
		}
	case 4:
	case 6:
	case 9:
	case 11:
		{
			return 30;
		}
	case 2:
		{
			if (IsLeapYear(nYear))
			{
				return 29;
			}
			else
			{
				return 28;
			}
		}
	}
}
unsigned int DayOfWeeks(unsigned int nYear,unsigned int nMonth,unsigned int nDay)
{
	unsigned int nCount = 0;
	for (unsigned int i = 1;i < nMonth;i ++)
	{
		nCount += MonthOfDays(nYear,nMonth);
	}
	nCount += nDay;
	
	float fVal = nYear - 1 + (float)(nYear - 1) / 4 + (float)(nYear - 1) / 100 +(float)(nYear - 1) / 400 - 40 + nCount;

	return (int) fVal % 7; 
}